FIG. 6 is a diagram showing an electromagnetic operation device for a power switching apparatus (vacuum circuit breaker) disclosed for example in Japanese Domestic Re-Publication No. WO2005/111641 (Patent Document 1).
Using FIG. 6, a configuration of the conventional electromagnetic operation device for a vacuum circuit breaker will be described.
A vacuum switch tube (called also as a vacuum valve) 50 constituting the vacuum circuit breaker has a switching contact 51 accommodated in a vacuum vessel. The switching contact 51 is composed of a fixed contact 51a and a movable contact 51b, and in the contact open state, the fixed contact 51a and the movable contact 51b are placed opposite to each other with a given space therebetween.
To the movable contact 51b, a driving shaft 52 is fixed, so that the movable contact 51b and the driving shaft 52 constitute a movable section. The movable section is coupled to a movable core 61 in an electromagnetic operation mechanism 60 through a contact pressure spring and a spring seat 54.
The electromagnetic operation mechanism 60 has a movable core 61, a closing drive coil 62 and an opening drive coil 63.
The closing drive coil 62 serves to drive the movable contact 51b to thereby achieve the contact closed state, and the opening drive coil 63 serves to drive the movable contact 51b to thereby achieve the contact open state.
The closing drive coil 62 and the opening drive coil as driving magnetic coils are arranged in axial direction of the movable core 61 with a given distance therebetween. The movable core 61 is disposed centrally in the closing drive coil 62 and the opening drive coil 63, and movably in its axial direction.
A driving power supply unit 70 has a closing drive capacitor 71, an opening drive capacitor 72, a close command switch 73 and an open command switch 74.
When the close command switch 73 is turned on, a voltage charged in the closing drive capacitor 71 is applied to the closing drive coil 62, so that a current flows through the closing drive coil 62 to thereby cause a drive toward the contact closed state. Meanwhile, when the open command switch 74 is turned on, a voltage charged in the opening drive capacitor 72 is applied to the opening drive coil 63, so that a current flows through the opening drive coil 63 to thereby cause a drive toward the contact open state.
Note that, in FIG. 6, shown at 81 is a connection line, at 82 is a current measuring device, and at 83 is a contact depletion amount measuring device; however, since they are not relevant to the present invention, their description is omitted here.
A status recognition device disclosed in the above Patent Document 1, is to be equipped in the electromagnetic operation device which comprises a fixed core, a movable core configured movably with respect to the fixed core, and a magnetic coil that causes to move the movable core being magnetically excited by a driving power supply, to thereby drive an operational target instrument (vacuum switch tube) being coupled to the movable core, wherein the status recognition device includes a measuring means for measuring a current flowing through the magnetic coil or a voltage generated in the magnetic coil, and an exploring means for acquiring information about a change in a waveform outputted from the measuring means, to thereby estimate a status of the operational target instrument or the electromagnetic operation device on the basis of the information about the change from the exploring means.
In Patent Document 1, however, there is no description as to “occurrence of change in speed of the contact switching operation, due to a change in current flowing through the magnetic coil” that is caused by a temperature change of the magnetic coil (the opening drive coil, the closing drive coil) or the capacitor (the opening drive capacitor, the closing drive capacitor) in the electromagnetic operation device for a vacuum circuit breaker using the vacuum switch tube, as well as to “suppression of change in speed of the contact switching operation”.
Meanwhile, FIG. 7 is a diagram showing a configuration of an electromagnetic-repulsion drive switching device disclosed for example in Japanese Domestic Re-Publication No. W001/031667 (Patent Document 2).
The electromagnetic-repulsion drive switching device shown in FIG. 7 (that is, an electromagnetic operation device for a vacuum circuit breaker), is an electromagnetic-repulsion drive switching device which is configured to include a closing drive coil 101 and an opening drive coil 102 that are arranged opposite to an electrically-conductive repulsion member; and to make contact or separation between a fixed contact and a movable contact by way of an electromagnetic repulsion force produced between either one of the coils 101, 102 and the repulsion member, when a drive current is supplied selectively to either one of the coils 101, 102 from a capacitor 104 charged at a predetermined voltage by a charging power supply 103; wherein a voltage control means 105 is provided that controls an output voltage of the charging power supply 103 so that a peak value of the drive current falls in a predetermined range, against a temperature change of the capacitor 104.
In Patent Document 2, there is described that “the contact is operated stably and accurately by providing the voltage control means to thereby control a peak value of the drive current to fall in the predetermined range even if the temperature of the capacitor changes”.
That is, in Patent Document 2, there is described that change in speed of the contact switching operation is suppressed by controlling the magnitude of current flowing through the closing drive coil or the opening drive coil according to a temperature change of the drive capacitor for causing a current to flow through the closing drive coil or the opening drive coil.
However, even in Patent Document 2, there is no description as to suppression of change in speed of the contact switching operation caused by a change in surrounding temperature of the magnetic coil (the opening drive coil, the closing drive coil) in an electromagnetic operation device for a vacuum circuit breaker using a vacuum switch tube.    Patent Document 1: Japanese Domestic Re-Publication No. WO2005/111641    Patent Document 2: Japanese Domestic Re-Publication No. WO01/031667